From 6132d7bce3b7ccef283949e17cba04672c18ce94 Mon Sep 17 00:00:00 2001
From: Renz Christian Bagaporo <renz@espressif.com>
Date: Mon, 6 May 2019 19:57:45 +0800
Subject: [PATCH 1/2] cmake: restore ccache use when present

Closes https://github.com/espressif/esp-idf/issues/3116
---
 tools/cmake/project.cmake | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tools/cmake/project.cmake b/tools/cmake/project.cmake
index 034566e7f..1bf088c3f 100644
--- a/tools/cmake/project.cmake
+++ b/tools/cmake/project.cmake
@@ -83,6 +83,15 @@ macro(project name)
     # Now the configuration is loaded, set the toolchain appropriately
     idf_set_toolchain()
 
+    # Enable ccache if it's on the path
+    if(NOT CCACHE_DISABLE)
+        find_program(CCACHE_FOUND ccache)
+        if(CCACHE_FOUND)
+            message(STATUS "ccache will be used for faster builds")
+            set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE ccache)
+        endif()
+    endif()
+
     __project(${name} C CXX ASM)
 
     set(IDF_BUILD_ARTIFACTS ON)

From 261c5bf6a898dd8b5655dfe7c98d60f9caecf5bb Mon Sep 17 00:00:00 2001
From: Renz Christian Bagaporo <renz@espressif.com>
Date: Mon, 6 May 2019 19:58:06 +0800
Subject: [PATCH 2/2] ci: check that build uses ccache when present

---
 tools/ci/test_build_system_cmake.sh | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tools/ci/test_build_system_cmake.sh b/tools/ci/test_build_system_cmake.sh
index 1c0b0b3e3..2740d6448 100755
--- a/tools/ci/test_build_system_cmake.sh
+++ b/tools/ci/test_build_system_cmake.sh
@@ -372,6 +372,13 @@ EOF
     grep "$PWD/components/bootloader/subproject/main/bootloader_start.c" build/bootloader/compile_commands.json \
         || failure "Custom bootloader source files should be built instead of the original's"
     rm -rf components
+    
+    print_status "Check ccache is used to build when present"
+    touch ccache && chmod +x ccache  # make sure that ccache is present for this test
+    (export PATH=$PWD:$PATH && idf.py reconfigure | grep "ccache will be used for faster builds") || failure "ccache should be used when present"
+    (export PATH=$PWD:$PATH && idf.py reconfigure --no-ccache | grep -c "ccache will be used for faster builds" | grep -wq 0) \
+        || failure "ccache should not be used even when present if --no-ccache is specified"
+    rm -f ccache
 
     print_status "All tests completed"
     if [ -n "${FAILURES}" ]; then